Asthma morbidity and mortality has been a serious public health problem in the U.S. During 1980-1994, the self-reported prevalence rate for asthma increased 75%, with nearly 14 million persons reporting asthma during 1994. There were nearly 2 million emergency room visits for asthma in 1995, with African Americans displaying higher rates for emergency room visits than Caucasians. Nearly 7,000 deaths in 1998 in the U.S. were due to asthma, and U.S. adults lost nearly 3 million workdays and U.S. children lost nearly 10 million school days in 1998 due to asthma. The Asthma Clinical Research Network (ACRN) has played, and will continue to play, a significant role in reducing the impact of asthma morbidity and mortality. The ACRN will conduct multiple multicenter clinical trials for evaluating current and novel therapies for individuals with asthma and rapidly disseminate the findings. This application from The Pennsylvania State University for the ACRN Data Coordinating Center lists six specific aims that will enable the ACRN to attain its objectives: (1) provide biostatistical leadership and scientific coordination; (2) establish and maintain the ACRN computer network and web site; (3) design and maintain the ACRN data management system; (4) develop and maintain the ACRN data quality assurance and monitoring program; (5) provide project management and administrative support; (6) provide oversight and management of data acquisition from biological samples. The DCC will assume leadership for the biostatistical aspects of optimizing trial designs that increase accuracy and precision, projecting sample sizes, selecting randomization schemes, analyzing data, and developing presentations/publications. Scientific coordination will include collaborating on protocol development, developing/leading training sessions, developing certification criteria, developing the Manuals of Operations (MOPs), collaborating on recruitment/retention strategies, and resolving questions from the Clinical Centers (CCs). The DCC will establish the ACRN computer network using the Internet and any existing networks at the CCs. The DCC will design and maintain a distributed data management system based on a wide-area network and world-wide web implementation of ORACLE data bases. The DCC will develop high-quality data collection forms, MOPs, and subject handouts. The DCC will track ACRN progress, organize all meetings/conferences, and coordinate training sessions and site visits.